Whether you think that you can, or that you can’t, you are usually right. (Henry Ford)

The full use of your powers along lines of excellence. (definition of happiness by John F. Kennedy)

Each problem that I solved became a rule which served afterwards to solve other problems. (Rene Descartes, Discours de la Methode)

Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away. (Antoine de Saint Exupery)

I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use. (Galileo Galilei)